RCW 49.28.140

(1) No employee of a health care facility may be required to work overtime. Attempts to compel or force employees to work overtime are contrary to public policy, and any such requirement contained in a contract, agreement, or understanding is void.

(2) The acceptance by any employee of overtime is strictly voluntary, and the refusal of an employee to accept such overtime work is not grounds for discrimination, dismissal, discharge, or any other penalty, threat of reports for discipline, or employment decision adverse to the employee.

(3) This section does not apply to overtime work that occurs:

(a) Because of any unforeseeable emergent circumstance;

(b) Because of prescheduled on-call time;

(c) When the employer documents that the employer has used reasonable efforts to obtain staffing. An employer has not used reasonable efforts if overtime work is used to fill vacancies resulting from chronic staff shortages; or

(d) When an employee is required to work overtime to complete a patient care procedure already in progress where the absence of the employee could have an adverse effect on the patient.